For the last several months you have been looking and seem to kind of be all over the place trying to figure out what you want. I actually admire the fact that you haven't "jumped" into something you will regret but are refining your search to find out what works best for you. Have you considered renting some different types of boats to find out if you really liked boating and what kind of boat fits your and your husband's lifestyle best. You seem to have moved up from a 14 footer to something a little larger. You will probably be trailering said boat, so it can't be too big. You want something reliable that you can swim, fish, boat, and lay out in the sun on. And you want to be in lakes, rivers, and ocean. It was for just 2 people and now it seems to be for up to 4 people. None of this is bad, but you are covering a lot of territory!
Do you have a budget? How much experience boating do you and your husband have? I remember you said you had a machine shop so you could manufacture parts, but how much mechanical and repair abilities do you and your husband have and how much time do you have in fixing/modifying a boat?
These are just some questions to help us all help you in giving you advice. Nothing that you have said has been wrong or bad, I am just trying to clarify. Personally, I have been boating for almost 60 years and spent about 5 years as an inland waterways licensed captain of a 60 foot tour boat. Understand we just want to help you clarify your needs/wants so you can get as close to what you need the first time. Just be aware that whatever you get, in a few years you will know more clearly what you want and it will probably be about 2 feet longer than what you will first get! That is called two footitis! It is a common malady in boating circles ... it is very contagious! You have been warned! LOL!